A Merlin restraining a Rock Pigeon in true raptor fashion. A 2011 study in the journal PLoS ONE hypothesized that Velociraptor and its relatives used their iconic sickle claws to pin prey in the same manner that falcons and hawks use today. Photo by the author.

The Dinosaur at Your Bird Feeder: Uncovering the Jurassic Origins of Modern Birds, By Jay Cooney

The red earth of northern New Mexico is a portal into deep-time, containing clues about the dawn of a lineage that brings song, color, and windborne motion to our lives today. At Ghost Ranch, paleontologists have unearthed over 1,000 skeletons belonging to Coelophysis, a carnivorous dinosaur that lived 252-201 million years ago. In addition to being New Mexico’s state fossil, Coelophysis represents the earliest known dinosaur to possess a furcula: the wishbone recognizable from Thanksgiving tradition. Once considered unique to birds, the presence of this anatomical feature in dinosaurs has helped transform our understanding of their evolutionary affiliations. Since the 1960s, fossil discoveries have confirmed the scientific consensus that birds evolved from the group of predatory dinosaurs known as theropods; existing today as surviving members of the Maniraptoran lineage that included Velociraptor of Jurassic Park fame. Birds are living dinosaurs, carrying the dynasty’s evolutionary epic into the soaring present.

In 1969, fossils of a raptorial theropod dinosaur called Deinonychus provided a long sought-after piece to the puzzle of bird evolution. A century earlier, the discovery of a    toothy, archaic bird dubbed Archaeopteryx roused theories that birds evolved from reptilian precursors during the Jurassic period 201-143 million years ago. When compared with Deinonychus specimens, complete with avian features like a furcula and hollow bones, Archaeopteryx acts as a ‘transitional species’ between birds and their theropod ancestors. As paleozoologist Darren Naish discusses in Dinopedia, Jurassic birds were originally just one of many indistinguishable groups of maniraptoran dinosaurs. The discovery of the clearly-agile Deinonychus also inspired a ‘Dinosaur Renaissance,’ painting a new picture of dinosaurs as bird-like in their active behavior and warm-blooded physiology. Rather than lumbering lizards, a theropod like T. rex maybe more accurately imagined, as paleontologist Robert Bakker dramatically put it, as a “20,000-pound roadrunner from Hell.”

Another paleontological breakthrough demonstrates that, rather than being a trait exclusive to modern birds, many earlier dinosaurs were feathered. In 1996, Jurassic-era fossil discoveries in Liaoning, China revealed well-preserved maniraptorans adorned in feathers. Most remarkably, Microraptor possessed wings on its forelimbs and hindlimbs, likely allowing it to soar across canopies. Feathers have since been identified in numerous species like Velociraptor and the T.rex-relative Yutyrannus, likely functioning for display and thermoregulation. The recent discovery of fossilized pigment packages called melanosomes allows us to discern feather color, like the iridescent-black of Microraptor. These finds have inspired paleo-artists to illustrate dinosaurs with all the extravagance of modern birds in books like All Yesterdays. Birds weathered the extinction of all other dinosaurs and went on to become the most diverse group of land vertebrates. Peering into this deep-time story can instill humility: the Earth was not holding its breath before our arrival, nor awaiting our dominion to bring it utility and purpose. We are one branch on the tree of life, able to contemplate our kinship with all organisms, and we share the planet with one of the most dazzling lineages. When we watch a Greater Roadrunner stride across the desert in pursuit of prey, or meet the piercing gaze of a Red-tailed Hawk, we are in the realm of dinosaurs.

Jay Cooney is a Naturalist at Wild Birds Unlimited of Santa Fe